If you have had your corydoras catfish paste clusters of eggs on your tank wall, and you want to save them from their hungry parents, this is for you. We do not know much about cories, but we are currently raising some fry we decided to save. This is the method we have been using, and it is working for us.
*NOTE: female corydoras are larger and more rounded than the males*
This info has been gathered from forums and websites and tested by us. We have only been raising cory fry for 1 week, so this article should not be your stand-alone guide.
Once the eggs are hard enough, we scrape them off the inside of the tank into a plastic sandwich bag filled with the tank water, with pin-holes in it for air flow, then let it hang from the inside of the tank by placing the tank lid down on the upper part of the bag to keep it in place.
When they hatch, we move them to a 2.5 gallon mini-bow (grow-out tank) of their own, that has a mini-heater, gravel, and plants in it. *WARNING: do not put them in with other tropical fish, they may get eaten* 5 to 10 percent water changes should be done every one to two days. We do not have a filter in yet, because the mini-bow came with a more powerful filter than reccomended for fry. A sponge filter is reccomended. If you can not get a sponge filter, put a special sponge cover (or pantyhose) over the filter intake for protection, but we will not do this until the fry are about two weeks old. We have had them for only one week now. *DO NOT keep the babies in a small tank once they are grown. They don't stay tiny forever, in fact, they grow very quickly. Once they are too big for the 2.5, thay must be in a suitable sized tank with suitable tank-mates.*
You may be told to do otherwise, but this is what we are doing: we finely crush up regular tropical fish food to make a fine powder, and sprinkle some in the water at feeding time, making sure to swoosh some of it down into the bottom of the tank. Frequent, small feedings are better than large, twice-a-day feedings when they are still small. They should be fed three or four times a day. We were told to feed the fry baby brine shrimp (bbs), but that doesn't work out for us. This method, however, does.
After one week the babies are doubled or tripled in size, and they should be very friendly and act just like their parents. They will still hide, but will more often be swimming up and down the side of the tank, or resting on plastic plants. You can now see their whiskers, their mouths, and their spots. Keep treting them like babies until they are large enough to eat regular food, I am told this is after about two months.
We have already hatched out the second batch of eggs, they hatched last night. When they were put into the mini-bow, the week-old babies got all exited. At one week the are nowhere near big enough to eat up their one-day-old siblings, so it is safe to hatch out more than one batch at a time.
Have fun cory raising!
*this information is from a fisrt-time cory breeder and should not be considered expert advice, but it works*